Far beneath the great seas depths, there reside seven submarines, they are basically wooden barrel type objects, You can sail up to them and enter them and figh for a great sometimes emense treasure. Some of these submarines are very challenging some are fairly easy. After you defeat every last enemy a ladder will drop that takes you to the treasure.

Sub. Guide:North Fairy Island: After you defeat all of the enemies on board, you will get the 'Treasure Chart #22'

Cresent Moon Island: After you defeat all of the enemies on board, you will get the 'Treasure Chart #9'

Flight Control Platform: After you defeat all of the enemies on board, you will get the 'Platform Chart'

Six-Eye Reef: After you defeat all of the enemies on board, you will get a 'Piece of Heart'

Bomb Island: After you defeat all of the enemies on board, you will get an 'Empty Bottle'

Headstone Island: After you defeat all of the enemies on board, you will get the 'Treasure Chart #14'

Five-Star Isles: After you defeat all of the enemies on board, you will get a 'Piece of Heart'